[TenTec] 9420 Power Supply Question

[Ken Brown]

The lables on my schematic for the 9420 show where the 3 non-ground 
wires of the transceiver connector go, to HI I, LO I and PWR ON. Putting 
a "load" (perhaps a short to ground) on the PWR ON lead would turn on 
Q1, and then everything that happens when the amplifier power switch 
connects the other PWR ON to the +REG would happen just the same. What 
is unclear to me is how the Omni VI wiring does this.

>It looks to me like the only way to turn the 9420's 4 separate power
>supplies on it to apply +13v to pin 3 of the 12-pin plug.
>
>But that doesn't make much sense because then the Herc would always have to
>be on before you could turn the Omni VI on.  Ten-Tec usually does logical
>stuff so there must be some trick in how the 4-pin is wired.  Unfortunately
>there's no description and the drawings are vague (showing only 1 line
>between the 4-pin plug and the P.S.).
>
>
>  
>
>> The transceiver "power on" is activated by connecting a load to this 
>>"power on" lead. The text does not say what they mean by a load, and 
>>it does not say just to ground it. I'll look at my Omni VI manual and 
>>see what it connects to pin 3.
>>    
>>
>
>I am not getting this. I does not help that my Omni VI manual does not 
>have pin numbers on the DC Power Input Board schematic. I don't see how 
>the power switch on the Omni VI can turn the 9420 on and off. It looks 
>like just plugging in Omni VI into the 9420 would turn it on, regardless 
>of the power switch postion. I have never tried using the 9420 to power 
>the Omni. Never made up a cable to do it. Still I would like to 
>understand this circuit, in case I ever want to use it that way. Anybody 
>out there who can clarify this?
>
>DE N6KB
>
>
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